1. Technological Field
The described technology generally relates to a method for determining a control set point of an aircraft, the control set point being intended to be transmitted to at least one avionics system from at least one actuator control system and at least one guidance system.
2. Description of the Related Technology
In order to vary the acceleration of a fixed-wing aircraft, the flight crew may generally act on the thrust, the drag, and the tractive force or braking force of the wheels on the ground. In order to act on the thrust, they generally have at their disposal an auto-thrust system, also known as auto-throttle capable of automatically maintaining a set point speed or a thrust level via control of the engines. The thrust can also be used on the ground in order to decelerate via the “reverse” function. In order to act on the drag, the crew generally have at their disposal an airbrake system used in flight or on the ground beyond a certain speed. On the ground, the crew may also act on the tractive force or braking force of the wheels so as to further modify the ground acceleration of the aircraft.
In order to cause the varying of acceleration of a rotary wing aircraft, the crew generally have at their disposal a collective control lever which, by acting in tandem with an engine control system such as a Full Authority Digital Engine Control (FADEC), provides the ability to cause varying of the thrust.
During the flight, at the time of a change in flight path trajectory, a variation in thrust or drag is necessary for maintaining the speed of the aircraft. Typically, the aircraft assumes the slope desired by the crew and in response thereto the thrust and drag are accordingly adjusted to the extent of their achievable domains in order to maintain the speed of the aircraft. However, it sometimes happens that the thrust and/or the drag achievable by the actuators of the aircraft is insufficient to compensate for the variation in slope required by the crew and thus to maintain the ordered speed or acceleration. In such situations, the crew must adjust the slope of the aircraft in response thereto if they wish to maintain the speed of the aircraft or to satisfy the ordered acceleration, which requires constant vigilance by the crew and is likely to bring about dangerous situations.
There is therefore a need to set in place a capability for viewing the performance domains that are achievable by an aircraft and for servo-controlling the guidance set points selected by the crew on the performance domains achievable by the aircraft.
It is known from the documents U.S. Pat. No. 6,469,640 B and US 2005/0261810 A display devices for displaying thrust levels accessible by an aircraft. The document US 2011/0238240 A in particular, describes a display device that enables the pilot to directly view the range of energy variation attainable by an aircraft.
However, these display devices only provide a visual aid to the crew.